Pollen and non-pollen palynomorph preservation in the dung of the Greater One-horned Rhino (Rhinoceros unicornis), and its implication to palaeoecology and palaeodietary analysis: A case study from India

The Greater One-horned Rhino of India is an endangered species. We investigate the pollen and non-pollen palynomorphs preserved in rhino dung collected from a communal rhino dung midden in Kaziranga National Park to document the vegetation composition and dietary habits of this rhino. The palynodata reflects the dominance of nonarboreals over arboreals from forested and grassland areas respectively. The arboreals include a mixture of evergreen, riparian, and deciduous taxa, which are strongly indicative of different types of forest in the park. The high presence of grass pollen and phytoliths in the rhino dung was marked and confirmed that grass is the primary food of the rhino. Diatoms and Thecamoeba in the rhino dung assemblage was suggestive of the ingestion of huge amount of water and the water logged condition in parts of the park. Energy dispersive spectroscopy analysis indicated that the silica contained in rhino dung sample was high in comparison to the others elements and determination of its presence is useful for understanding rhinoceros' habits. The generated data will be helpful and to serve as a guideline for subsequent palaeoecological and palaeodietary studies in the park.